Are Mushroom Corals Aggressive?

Your mushroom coral has arrived, and now you are beginning to worry about the other corals in your aquarium after what happened last time – chemical warfare!

Mushroom corals are one of our favorite soft corals, and when you see them, I’m sure you will agree! Not only are mushroom corals beautiful, but it is also their easy care requirements that make them very popular in the hobbyist world. 

Can Mushroom Corals Be Aggressive?

Mushroom corals are mostly peaceful, as most mushrooms do not have long stinging sweeper tentacles. However, they are more aggressive in terms of dominating space. As mushroom corals can move, they can easily grow over any nearby corals, encrusting on any surface they wish. 

Even though mushroom corals do not have long sweeper tentacles like most LPS (large polyp stony) corals, they do have a natural defense mechanism to protect themselves, and who blames them, being a coral in the wild can be a challenging time. 

This defense mechanism cannot be turned off in aquariums, because it is in your mushroom coral’s nature. If your mushroom coral feels threatened, a small stinging tentacle will emerge from its cap, stretching, and touching any neighboring corals. 

Their tentacle doesn’t seem to have powerful nematocysts that usually pose an issue, however, the tentacle still contains powerful chemicals. Your mushroom coral’s stinging tentacle is especially harmful to other types of soft corals and also some SPS (small polyp stony) corals. This is why placement is key, despite a mushroom coral’s habit to move around aquariums. 

Which Corals Are Compatible With Mushroom Corals?

You probably want to add other types of corals to your aquarium, because let’s face it, you want to create that mini-ocean display right… But, before you dive in, you need to consider the compatibility between corals. 

While your corals may be playing happy families at the start, give them time to grow, and an aquarium soon becomes a crowded environment where corals will outcompete other coral species for space. 

What we do know is that mushroom corals such as rhodactis (hairy mushroom coral) will win a fight against zoanthids and palythoa corals, and will also try to take a swing at acroporas and acans. 

To avoid conflict inside your aquarium, it is best to avoid mixing these corals. However, if you have a big reef aquarium, then you can create different areas, separating the corals, but remember that mushroom corals can move if they feel like it, let’s just say, they are fairly unpredictable!

Can You Place Mushroom Corals Together?

Mushroom corals seem to be tolerant of each other, therefore, you should have no issues placing a mixture of mushrooms in your aquarium, especially if the mushrooms are from the same genus. 

Some hobbyists have mentioned that because Ricordea mushrooms can be quite aggressive, they do often touch other mushroom corals. However, no mushroom seems to get hurt in the process, instead, if a mushroom coral feels uncomfortable, it will move somewhere else in the aquarium. 

Signs Of Coral Aggression

When a coral becomes subject to an aggressive neighbor, it will retract its polyps to protect itself. They may also start turning white from the damage, shrivel up, or in worst cases, the coral will die. 

Are Mushroom Corals Also Aggressive Towards Fish?

Most reef-friendly fish will live in harmony with your mushroom coral, however larger mushroom corals like the elephant ear (Amplexidiscus fenestrafer) can quickly engulf small fish that get too close. 

Be particularly careful when keeping clownfish and other anemone fish in your aquarium with mushroom corals. Monitor both their behavior, and move them if things get a little heated. 

How To Prevent Mushroom Corals Becoming Aggressive?

It is highly recommended you leave at least 2 inches between your mushroom corals and any other type of coral you may have (mushrooms seem to be fine next to each other). 

It is best to place your mushroom corals lower down in your aquarium on an isolated rock. This should deter your mushroom corals to find a more suitable location and potentially start chemical warfare. 

It is also important to note that like all corals, mushroom corals contain an exterior slime that can irritate your skin. This slime can be very toxic to humans, therefore, always handle your mushroom coral (or any corals for that matter) with extra caution and care. Wear some protective equipment such as rubber gloves and eye protection to prevent a visit to the ER. 


Mushroom corals are not aggressive in terms of attacking neighboring corals until death, however, they will climb over any corals that get in their way, often releasing a defensive chemical in the process, so they are considered semi-aggressive. 

Before deciding where to place your mushroom coral, check if it has long sweeper tentacles, and if it does, allow at least 2 inches between other corals. Frequently monitor your mushroom corals’ behavior, and if things start to get out of hand, consider moving them or removing them from your aquarium if they cause utter chaos. 

  • Roy Lee

    I have an unhealthy obsession with reef keeping and maintaining successful tanks. If you haven't noticed from the website, I love everything related to saltwater tanks like coral, fish, and everything else in between. Lee Roy

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